You ladies are probably more clued up than me but for the first 6 months of TTC me and DH were using KY to help smooth things along when we were DTD (TMI?). I had no idea it could have such detrimental effects on fertility/sperm motility. According to this research paper, apparently saliva also has a toxic effect (www.ncbi.nlm.nih.gov/pubmed/9886513). 
I thought I would post this on here just in case anyone doesn't know. I know some people are using preseed which I have heard is absolutely fine. You are probably all thinking I am a fool for not knowing but I presumed as it wasn't a spermicide it would be ok. Anyway we got a BFP the month we didnt use it (subsequently MC'd but thats by the by). We will never touch the stuff again! We'll just have to put a bit more effort in to DTD this month IYKWIM 